Fig. (4).

miR-196 regulates Hox gene expression and patterning of the A-P axis. A. miR-196 (yellow) regulates Hox target expression (blue; Hoxb8) both within and at the posterior boundary of its endogenous expression. Note: the regulation of Hoxb8 at more anterior locations may not be at the embryonic stage depicted, but rather in precursor cells of this region at early stages of development. B. Summary of miR-196 overexpression and morpholino knockdown results in zebrafish. Relative to wild type, miR-196 overexpression or knockdown regulates pharyngeal arch number as well and the number of pre-caudal rib bearing vertebrae. In addition, miR-196 overexpression results in complete pectoral fin loss. Vertebral regions are color coded, weberian apparatus (orange), rib-bearing precaudal (pink), caudal (teal) and tail (purple) vertebrae.